Field Trial: Killing the Nissan Leaf's Battery

For all the talk of range anxiety with battery-electric cars, we've gotten nervous in our Nissan Leaf only a couple of times since Cars.com purchased it in February, and thanks to minor adjustments in speed or heater setting, we averted drama each time. Curious about the experience of a dead battery and Nissan's promise of free towing for owners who run "dry," we intentionally set out to overextend ourselves.

We began driving with the instrument panel predicting about 16 miles of range, and all was normal until the range indicator hit eight miles and began blinking and a voice chimed in, "Low battery charge." If those warnings weren't enough, the Leaf's main instrument panel illuminated a red gas pump icon and filled the trip computer's display with the words "Battery level is low." A general warning icon appeared in the upper-tier instrument panel, closer to one's line of sight, and even the center touch-screen navigation system had a "Low Battery" flag, which you could press to get a full-screen warning and the option to search for nearby charging stations.

I don't know what more Nissan could have done to warn the driver, short of applying a mild electric shock, but that wouldn't help the range issue.

At a range of roughly four miles, the voice warned, "Very low battery charge. Would you like to search for a nearby charging station?" The range indicator no longer showed a number at all, as if to say, "You're on your own." We had traveled roughly 16 miles at this point, so we were flying blind. The LCD screen had popped up a warning window with the option to search for a charging station. We hit the yes button, and the closest location was multimedia editor Eric Rossi's house that was 5.9 miles away. The car had automatically stored the location the first time it charged there.

Would we make it? Well, that wasn't the goal; we wanted to kill it, so we stuck to side roads, not wanting to push it off a highway. Minutes ticked by. The moderate speeds and cool weather kept the Leaf going and going, and we began to wonder if our 6.4-liter V-8-powered Dodge Challenger chase car would run out of fuel first.

After about four more miles, we reached the final milestone — the elusive turtle mode. The warning voice said, "Power output is being limited." The trip computer display cycled between "Motor power is limited" and "Battery level is low," and an orange turtle icon (or is it a tortoise?) appeared front and center.

The power was indeed limited. The Leaf accelerated at a rate of roughly 1 mph per second, so the fastest I ever got it going on side streets was 30 mph between stop signs. This mode is intended exclusively to get you to the side of the road, not to continue driving. We continued driving.

We got more than another mile out of the Leaf, finally coming to rest at the top of a modest incline having traveled 21.6 miles since the experiment began. The car went into Neutral and wouldn't go back into Drive or Reverse. Cars.com had killed the electric car. The lights and all instruments stayed on, and the air conditioning continued blowing.

At 3:45 p.m. I phoned roadside assistance and pressed 1 to indicate a dead battery, wondering if it represented the conventional battery or EV type. A live operator came on and asked all the relevant questions. She said towing was covered under warranty and we would be towed to a Nissan dealer. I asked if we could instead be brought to Eric's house, a mere 2 miles away. She said yes, any distance less than 50 miles is allowed.

With my permission, she used my cellphone to pinpoint our location within feet (creepy) and said I'd get a confirmation call soon. Eight minutes had passed since I dialed. At 4 o' clock an automated call said the tow truck was roughly an hour away. It actually arrived at 4:40 p.m., installed the Leaf's front bumper tow hook and winched it onboard. The driver dropped the car off — practically all the way into Eric's tight garage — and was gone by 5:27.

From the time we ground to a halt around 3:40 p.m., less than two hours had passed. It was a drag, but it was free and otherwise painless. We think falling two miles short of our destination was a realistic scenario for a driver who misjudges his own electric vehicle’s range, and it underscored how attractive a roadside recharge would be, as we demonstrated in a previous field trial. With that option, we could have added enough juice to get home in the amount of time it took to complete the paperwork for our tow-truck driver. The car never would have been loaded onto the truck, and we would have shaved another 30 minutes off the experience.

It could have been worse, though. If we weren't so close to Eric's house, we would have had to go to a dealership or other Level 2 charging point where the car would have to remain for a few hours or even overnight. That would have been more inconvenient than any conventional dead battery or empty fuel tank.

A final note: Though we went 21.6 miles at the end, following an estimate of 16 miles, the full range from the previous day's full charge was 72 actual miles after the car had estimated 108 miles. Some of that driving was on the highway, not the easy lower-speed driving we did during the test, but the weather was close to optimal.

Having definitively tested the actual range as opposed to the Leaf's starting and ending estimates, it seems like the EPA-estimated range of 73 miles is much closer to reality than is Nissan's marketing claim of "up to" 100 miles. This has been our suspicion all along.

Another interesting side note: After being charged for three hours at Level 1 — the 120-volt charging cord that usually adds up to five miles of range per hour — the Leaf estimated only four miles. We must have really run that thing down.

Comments

Using the A/C even on low will affect your range, as you saw going from an estimated 18-16 when it switched on. It may have cost you 10 miles of range going by those figures. Obviously extending range was not your point in this video.

What is wrong with Nissan's "up to 100 miles"? Only if you can show that it is wildly inaccurate by driving much *farther* than 100 miles, you can prove them wrong. As long as you stay below 100 miles per charge, Nissan is right...
Mixing Freeway and stop-and-go to get 72 miles range sounds very reasonable. Typical consumption for a vehicle like the Leaf is 250Wh/mi so its 24kWh pack should theoretically give a range of 96 miles when driven to expend all electric power. But I presume that Nissan is smarter than that and allows 10 or 20% remaining capacity in the pack to avoid killing cells and allowing you to run the AirCo for a little longer even after the car stops.
I bet that if you set out on a continuous 35 MPH without any additional power draw (no lights, no airco, no fans, ...) and your wheels aligned for zero toe and max tire pressure, then your hypermiling may prove Nissan wrong by easily going 120 or even 150 miles... New challenge?
Regarding the way the Leaf handles, this is way better than any liquid fuel vehicle that simply dies, here you can go on for miles after receiving warning after warning. And you can solve the problem by simply plugging in at the nearest store or friendly neighbor to get enough juice to make it home again.
BTW, I am waiting for someone to build a universal EV fast charge dyno. This can be a single-wheel roller with an OBD or CAN plug to put the car into regenerative braking (light brake pedal pressure simulation) and fast-charging the EV battery pack with around 30kW. This is the equivalent of 2 miles added per minute. Even if you are 10 miles from home, you can proceed after only 5 minutes of this type of charging! Since it does not rely on a plug, only on moving a drive wheel, it is universal for any EV that has regenerative braking capability. Short of having such a dyno, you can tie an EV to any other vehicle and tow it around for a few minutes while the EV is lightly braking to achieve the same effect.
The easiest way to create such a dyno would probably be a set of rollers where two cars can be parked side by side, each with one drive wheel on the rollers, so one can deliver power and the other receive power into its battery pack.

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